Trends and an Online Survey on the Use of Rigid Bronchoscopy in Korea

Background@#Although almost all interventional pulmonologists agree that rigid bronchoscopy is irreplaceable in the field of interventional pulmonology, less is known about the types of diseases that the procedure is used for and what difficulties the operators face during the procedure. The purpose of this study is to evaluate what diseases rigid bronchoscopy is used for, whether it is widely used, and what challenges the operators face in Korea. @*Methods@#We enrolled 14 hospitals in this retrospective cohort of patients who underwent rigid bronchoscopy between 2003 and 2020. An online survey was conducted with 14 operators to investigate the difficulties associated with the procedure. @*Results@#While the number of new patients at Samsung Medical Center (SMC) increased from 189 in 2003–2005 to 468 in 2018–2020, that of other institutions increased from 0 to 238.The proportion of SMC patients in the total started at 100% and steadily decreased to 59.2%.The proportion of malignancy as the indication for the procedure steadily increased from 29.1% to 43.0%, whereas post-tuberculous stenosis (25.4% to 12.9%) and post-intubation stenosis (19.0% to 10.9%) steadily decreased (all P for trends < 0.001). In the online survey, half of the respondents stated that over the past year they performed less than one procedure per month. The fewer the procedures performed within the last year, the more likely collaboration with other departments was viewed as a recent obstacle (Spearman correlation coefficient, r s = −0.740, P = 0.003) and recent administrative difficulties were encountered (r s = −0.616, P = 0.019). @*Conclusion@#This study demonstrated that the number of patients undergoing rigid bronchoscopy has been increasing, especially among cancer patients. For this procedure to be used more widely, it will be important for beginners to systematically learn about the procedure itself as well as to achieve multidisciplinary consultation.

Efficacy of lower dose pirfenidone for idiopathic pulmonary fibrosis in real practice: a retrospective cohort study

Background/Aims@#Pirfenidone slows the progression of idiopathic pulmonary fibrosis (IPF). We investigated its efficacy and safety in terms of dose and disease severity in real-world patients with IPF. @*Methods@#This multicenter retrospective cohort study investigated 338 patients treated with pirfenidone between July 2012 and March 2018. Demographics, pulmonary function, mortality, and pirfenidone-related adverse events were also investigated. Efficacy was analyzed according to pirfenidone dose and disease severity using linear mixed-effects models to assess the annual decline rate of forced vital capacity (FVC) and diffusing capacity of the lungs for carbon monoxide (DLCO). @*Results@#The mean %FVCpredicted and %DLCOpredicted values were 72.6% ± 13.1% and 61.4% ± 17.9%, respectively. The mean duration of pirfenidone treatment was 16.1 ± 9.0 months. In the standard dose (1,800 mg/day) group, the mean %FVCpredicted was −6.56% (95% confidence interval [CI], −9.26 to −3.87) per year before, but −4.43% (95% CI, −5.87 to −3.00) per year after treatment with pirfenidone. In the non-standard lower dose group, the mean %FVCpredicted was −4.96% (95% CI, −6.82 to −3.09) per year before, but −1.79% (95% CI, −2.75 to −0.83) per year after treatment with pirfenidone. The FVC decline rate was significantly reduced, regardless of the Gender-Age-Physiology (GAP) stage. Adverse events and mortality were similar across dose groups; however, they were more frequent in GAP stages II–III than in the stage I group. @*Conclusions@#The effect of pirfenidone on reducing disease progression of IPF persisted even with a consistently lower dose of pirfenidone.

Interpretation of Pulmonary Function Tests and Optimization of Inhalation Therapy / 대한내과학회지

Spirometry, also called office-based pulmonary function testing, is a useful tool for diagnosis and classification of lung disease. Here, we outline a simple stepwise approach for interpretation of spirometry results. The first step is to determine the forced expiratory volume in a one second/forced vital capacity (FEV1/FVC) ratio. If airflow is limited, a bronchodilator is administered followed by reassessment. The next step is to determine whether FVC is low; an observed decrease in FVC indicates a restrictive patten. For patients with obstructive disease, inhalation medication is needed. Therefore, this review also describes the most appropriate inhalation device for each patient and the correct use of the device to maximize inhalation therapy benefits.

Interpretation of Pulmonary Function Tests and Optimization of Inhalation Therapy / 대한내과학회지

Spirometry, also called office-based pulmonary function testing, is a useful tool for diagnosis and classification of lung disease. Here, we outline a simple stepwise approach for interpretation of spirometry results. The first step is to determine the forced expiratory volume in a one second/forced vital capacity (FEV1/FVC) ratio. If airflow is limited, a bronchodilator is administered followed by reassessment. The next step is to determine whether FVC is low; an observed decrease in FVC indicates a restrictive patten. For patients with obstructive disease, inhalation medication is needed. Therefore, this review also describes the most appropriate inhalation device for each patient and the correct use of the device to maximize inhalation therapy benefits.

Lung ultrasound for early diagnosis and severity assessment of pneumonia in patients with coronavirus disease 2019

Background/Aims@#Current evidence supports lung ultrasound as a point-ofcare alternative diagnostic tool for various respiratory diseases. We sought to determine the utility of lung ultrasound for early detection of pneumonia and for assessment of respiratory failure among patients with coronavirus disease 2019 (COVID-19). @*Methods@#Six patients with confirmed COVID-19 by reverse transcription-polymerase chain reaction were enrolled. All had undergone chest X-ray and chest computed tomography (CT) on the day of admission and underwent multiple point-of-care lung ultrasound scans over the course of their hospitalization. @*Results@#Lung ultrasound detected early abnormal findings of representative B-lines in a patient with a normal chest X-ray, corresponding to ground-glass opacities on the chest CT scan. The ultrasound findings improved as her clinical condition improved and her viral load decreased. In another minimally symptomatic patient without significant chest X-ray findings, the ultrasound showed B-lines, an early sign of pneumonia before abnormalities were detected on the chest CT scan. In two critically ill patients, ultrasound was performed to assess for evaluation of disease severity. In both patients, the clinicians conducted emergency rapid sequence intubation based on the ultrasound findings without awaiting the laboratory results and radiological reports. In two children, ultrasound was used to assess the improvement in their pneumonia, thus avoiding further imaging tests such as chest CT. @*Conclusions@#Lung ultrasound is feasible and useful as a rapid, sensitive, and affordable point-of-care screening tool to detect pneumonia and assess the severity of respiratory failure in patients hospitalized with COVID-19.

Hyperuricemia Is Not Predictive of Long-Term Outcome in Patients with Stable Chronic Obstructive Pulmonary Disease

BACKGROUND: Although the association of hyperuricemia with an increased risk of mortality has been demonstrated in the context of acute exacerbation of chronic obstructive pulmonary disease (COPD), the long-term outcomes of hyperuricemia have not been studied in the case of stable COPD.METHODS: We retrospectively analyzed baseline data of 240 men with stable COPD enrolled in the Korea Obstructive Lung Disease cohort. We evaluated associations between serum uric acid levels and clinical parameters, risk factors for all-cause mortality, and acute exacerbation of COPD.RESULTS: The mean age of subjects was 66.4 ± 7.7 years, and the median follow-up time was 5.9 years. We identified no significant difference in terms of lung function or laboratory findings between patients with hyperuricemia and those without. Serum uric acid level was negatively associated with systemic inflammation indicated by neutrophil–lymphocyte ratio (r = −0.211, P = 0.001). Univariate Cox regression analysis revealed hyperuricemia to not be associated with an increased risk of all-cause mortality in men with stable COPD (hazard ratio [HR], 0.580; 95% confidence interval [CI], 0.250–1.370; P = 0.213). In the multivariate Cox regression model, hyperuricemia was not an independent predictor of acute exacerbation (HR, 1.383; 95% CI, 0.977–1.959; P = 0.068).CONCLUSION: Among men with stable COPD, hyperuricemia is not an independent predictor of all-cause mortality or future acute exacerbation of COPD. These results differ from those of previous studies on patients with acute exacerbation of COPD.

Hyperuricemia Is Not Predictive of Long-Term Outcome in Patients with Stable Chronic Obstructive Pulmonary Disease

BACKGROUND@#Although the association of hyperuricemia with an increased risk of mortality has been demonstrated in the context of acute exacerbation of chronic obstructive pulmonary disease (COPD), the long-term outcomes of hyperuricemia have not been studied in the case of stable COPD.@*METHODS@#We retrospectively analyzed baseline data of 240 men with stable COPD enrolled in the Korea Obstructive Lung Disease cohort. We evaluated associations between serum uric acid levels and clinical parameters, risk factors for all-cause mortality, and acute exacerbation of COPD.@*RESULTS@#The mean age of subjects was 66.4 ± 7.7 years, and the median follow-up time was 5.9 years. We identified no significant difference in terms of lung function or laboratory findings between patients with hyperuricemia and those without. Serum uric acid level was negatively associated with systemic inflammation indicated by neutrophil–lymphocyte ratio (r = −0.211, P = 0.001). Univariate Cox regression analysis revealed hyperuricemia to not be associated with an increased risk of all-cause mortality in men with stable COPD (hazard ratio [HR], 0.580; 95% confidence interval [CI], 0.250–1.370; P = 0.213). In the multivariate Cox regression model, hyperuricemia was not an independent predictor of acute exacerbation (HR, 1.383; 95% CI, 0.977–1.959; P = 0.068).@*CONCLUSION@#Among men with stable COPD, hyperuricemia is not an independent predictor of all-cause mortality or future acute exacerbation of COPD. These results differ from those of previous studies on patients with acute exacerbation of COPD.

Hyperuricemia Is Not Predictive of Long-Term Outcome in Patients with Stable Chronic Obstructive Pulmonary Disease

BACKGROUND@#Although the association of hyperuricemia with an increased risk of mortality has been demonstrated in the context of acute exacerbation of chronic obstructive pulmonary disease (COPD), the long-term outcomes of hyperuricemia have not been studied in the case of stable COPD.@*METHODS@#We retrospectively analyzed baseline data of 240 men with stable COPD enrolled in the Korea Obstructive Lung Disease cohort. We evaluated associations between serum uric acid levels and clinical parameters, risk factors for all-cause mortality, and acute exacerbation of COPD.@*RESULTS@#The mean age of subjects was 66.4 ± 7.7 years, and the median follow-up time was 5.9 years. We identified no significant difference in terms of lung function or laboratory findings between patients with hyperuricemia and those without. Serum uric acid level was negatively associated with systemic inflammation indicated by neutrophil–lymphocyte ratio (r = −0.211, P = 0.001). Univariate Cox regression analysis revealed hyperuricemia to not be associated with an increased risk of all-cause mortality in men with stable COPD (hazard ratio [HR], 0.580; 95% confidence interval [CI], 0.250–1.370; P = 0.213). In the multivariate Cox regression model, hyperuricemia was not an independent predictor of acute exacerbation (HR, 1.383; 95% CI, 0.977–1.959; P = 0.068).@*CONCLUSION@#Among men with stable COPD, hyperuricemia is not an independent predictor of all-cause mortality or future acute exacerbation of COPD. These results differ from those of previous studies on patients with acute exacerbation of COPD.

Clinical Significance of Pleural Attachment and Indentation of Subsolid Nodule Lung Cancer / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Lung cancers presenting as subsolid nodule commonly have peripheral location, making the cancer-pleura relationship noteworthy. We aimed to evaluate the effect of pleural attachment and/or indentation on visceral pleural invasion (VPI) and recurrence-free survival. MATERIALS AND METHODS: Patients who underwent curative resection of lung cancer as subsolid nodules from April 2007 to January 2016 were retrospectively evaluated. They were divided into four groups according to their relationship with the pleura. Clinical, radiographical, and pathological findings were analyzed. RESULTS: Among 404 patients with malignant subsolid nodule, 120 (29.7%) had neither pleural attachment nor indentation, 26 (6.4%) had attachment only, 117 (29.0%) had indentation only, and 141 (34.9%) had both. VPI was observed in nodules of 36 patients (8.9%), but absent in nonsolid nodules and in those without pleural attachment and/or indentation. Compared to subsolid nodules with concurrent pleural attachment and indentation, those with attachment only (odds ratio, 0.12; 95% confidence interval [CI], 0.02 to 0.98) and indentation only (odds ratio, 0.10; 95% CI, 0.03 to 0.31) revealed lower odds of VPI. On subgroup analysis, the size of the solid portion was associated with VPI among those with pleural attachment and indentation (p=0.021). Such high-risk features for VPI were associated with earlier lung cancer recurrence (adjusted hazard ratio, 3.31; 95% CI, 1.58 to 6.91). CONCLUSION: Concurrent pleural attachment and indentation are risk factors for VPI, and the odds increase with larger solid portion in subsolid nodules. Considering the risk of recurrence, early surgical resection could be encouraged in these patients.

Comparing tuberculin skin test and interferon γ release assay (T-SPOT.TB) to diagnose latent tuberculosis infection in household contacts

BACKGROUND/AIMS: The tuberculin skin test (TST) and interferon γ release assay are currently used as diagnostic tools to detect latent tuberculosis (TB) infection; however, there are inconsistencies about the degree of agreement between the tests. We aimed to evaluate the concordance rate between the two tests in household contacts of a country with intermediate TB burden, where most people were vaccinated. METHODS: We recruited household contacts who spent > 8 hours daily with patients with microbiologically confirmed active pulmonary TB, and received both TST and T-SPOT.TB (Oxford Immunotec) simultaneously. The degree of agreement was analysed according to TST cutoff and Bacille Calmette-Guerin (BCG) vaccination status. Relevant factors were analysed to establish the association with TST or T-SPOT.TB. RESULTS: Among 298 household contacts, 122 (40.9%) were spouses, and 250 (83.9%) had received BCG vaccination. In the contact sources, 117 (39.3%) showed a positive result for acid-fast bacillus (AFB) sputum smear and 109 (36.6%) had cavities. The highest agreement rate of 69.5% and κ value of 0.378 were found with a 10 mm cutoff. Spouse, time interval from TB diagnosis to test, and AFB sputum smear positivity were significantly associated with a positive result for T-SPOT.TB. Sex, BCG vaccination, and cavity on chest computed tomography were related to TST positivity. CONCLUSIONS: The present study suggested it was not possible for TST and T-SPOT.TB to replace each other because of considerable discrepancy between the two tests in household contacts in a country with intermediate TB prevalence.

Comparing tuberculin skin test and interferon γ release assay (T-SPOT.TB) to diagnose latent tuberculosis infection in household contacts

BACKGROUND/AIMS: The tuberculin skin test (TST) and interferon γ release assay are currently used as diagnostic tools to detect latent tuberculosis (TB) infection; however, there are inconsistencies about the degree of agreement between the tests. We aimed to evaluate the concordance rate between the two tests in household contacts of a country with intermediate TB burden, where most people were vaccinated. METHODS: We recruited household contacts who spent > 8 hours daily with patients with microbiologically confirmed active pulmonary TB, and received both TST and T-SPOT.TB (Oxford Immunotec) simultaneously. The degree of agreement was analysed according to TST cutoff and Bacille Calmette-Guerin (BCG) vaccination status. Relevant factors were analysed to establish the association with TST or T-SPOT.TB. RESULTS: Among 298 household contacts, 122 (40.9%) were spouses, and 250 (83.9%) had received BCG vaccination. In the contact sources, 117 (39.3%) showed a positive result for acid-fast bacillus (AFB) sputum smear and 109 (36.6%) had cavities. The highest agreement rate of 69.5% and κ value of 0.378 were found with a 10 mm cutoff. Spouse, time interval from TB diagnosis to test, and AFB sputum smear positivity were significantly associated with a positive result for T-SPOT.TB. Sex, BCG vaccination, and cavity on chest computed tomography were related to TST positivity. CONCLUSIONS: The present study suggested it was not possible for TST and T-SPOT.TB to replace each other because of considerable discrepancy between the two tests in household contacts in a country with intermediate TB prevalence.

Who Dies after ICU Discharge? Retrospective Analysis of Prognostic Factors for In-Hospital Mortality of ICU Survivors

We investigated the causes of inpatient death after intensive care unit (ICU) discharge and determined predictors of in-hospital mortality in Korea. Using medical ICU registry data of Seoul National University Hospital, we performed a retrospective cohort study involving patients who were discharged alive from their first ICU admission with at least 24 hours of ICU length of stay (LOS). From January 2011 to August 2013, 723 patients were admitted to ICU and 383 patients were included. The estimated in-hospital mortality rate was 11.7% (45/383). The most common cause of death was respiratory failure (n = 25, 56%) followed by sepsis and cancer progression; the causes of hospital death and ICU admission were the same in 64% of all deaths; sudden unexpected deaths comprised about one-fifth of all deaths. In order to predict in-hospital mortality among ICU survivors, multivariate analysis identified presence of solid tumor (odds ratio [OR], 4.06; 95% confidence interval [CI], 2.01–8.2; P < 0.001), hematologic disease (OR, 4.75; 95% CI, 1.51–14.96; P = 0.013), Sequential Organ Failure Assessment (SOFA) score upon ICU admission (OR, 1.08; 95% CI, 0.99–1.17; P = 0.075), and hemoglobin (Hb) level (OR, 0.67; 95% CI, 0.52–0.86; P = 0.001) and platelet count (Plt) (OR, 0.99; 95% CI, 0.99–1.00; P = 0.033) upon ICU discharge as significant factors. In conclusion, a significant proportion of in-hospital mortality is predictable and those who die in hospital after ICU discharge tend to be severely-ill, with comorbidities of hematologic disease and solid tumor, and anemic and thrombocytopenic upon ICU discharge.

Intermediate risk of multidrug-resistant organisms in patients who admitted intensive care unit with healthcare-associated pneumonia

BACKGROUND/AIMS: Healthcare-associated pneumonia (HCAP) was proposed asa new pneumonia category in 2005, and treatment recommendations includebroad-spectrum antibiotics directed at multidrug-resistant (MDR) pathogens.However, this concept continues to be controversial, and microbiological data arelacking for HCAP patients in the intensive care unit (ICU). This study was conductedto determine the rate and type of antibiotic-resistant organisms and theclinical outcomes in patients with HCAP in the ICU, compared to patients withcommunity-acquired pneumonia (CAP) or hospital-acquired pneumonia (HAP). METHODS: We conducted a retrospective cohort analysis of patients with pneumonia(n = 195) who admitted to medical ICU in tertiary teaching hospital fromMarch 2011 to February 2013. Clinical characteristics, microbiological distributions,treatment outcomes, and prognosis of HCAP (n = 74) were compared tothose of CAP (n = 75) and HAP (n = 46). RESULTS: MDR pathogens were significantly higher in HCAP patients (39.1%) thanin CAP (13.5%) and lower than in HAP (79.3%, p < 0.001). The initial use of inappropriateantibiotic treatment occurred more frequently in the HCAP (32.6%) andHAP (51.7%) groups than in the CAP group (11.8%, p = 0.006). There were no differencesin clinical outcomes. The significant prognostic factors were pneumoniaseverity and treatment response. CONCLUSIONS: MDR pathogens were isolated in HCAP patients requiring ICU admissionat intermediate rates between those of CAP and HAP.

Outcome of Inhaler Withdrawal in Patients Receiving Triple Therapy for COPD / 결핵및호흡기질환

BACKGROUND: The purpose of this study was to document outcomes following withdrawal of a single inhaler (step-down) in chronic obstructive pulmonary disease (COPD) patients on triple therapy (long-acting muscarinic antagonist and a combination of long-acting beta2-agonists and inhaled corticosteroid), which a common treatment strategy in clinical practice. METHODS: Through a retrospective observational study, COPD patients receiving triple therapy over 2 years (triple group; n=109) were compared with those who had undergone triple therapy for at least 1 year and subsequently, over 9 months, initiated inhaler withdrawal (step-down group, n=39). The index time was defined as the time of withdrawal in the stepdown group and as 1 year after the start of triple therapy in the triple group. RESULTS: Lung function at the index time was superior and the previous exacerbation frequency was lower in the stepdown group than in the triple group. Step-down resulted in aggravating disease symptoms, a reduced overall quality of life, decreasing exercise performance, and accelerated forced expiratory volume in 1 second (FEV1) decline (54.7+/-15.7 mL/yr vs. 10.7+/-7.1 mL/yr, p=0.007), but there was no observed increase in the frequency of exacerbations. CONCLUSION: Withdrawal of a single inhaler during triple therapy in COPD patients should be conducted with caution as it may impair the exercise capacity and quality of life while accelerating FEV1 decline.

Diagnostic Value of Combining Tumor and Inflammatory Markers in Lung Cancer

BACKGROUND: Despite major advances in lung cancer treatment, early detection remains the most promising way of improving outcomes. To detect lung cancer in earlier stages, many serum biomarkers have been tested. Unfortunately, no single biomarker can reliably detect lung cancer. We combined a set of 2 tumor markers and 4 inflammatory or metabolic markers and tried to validate the diagnostic performance in lung cancer. METHODS: We collected serum samples from 355 lung cancer patients and 590 control subjects and divided them into training and validation datasets. After measuring serum levels of 6 biomarkers (human epididymis secretory protein 4 [HE4], carcinoembryonic antigen [CEA], regulated on activation, normal T cell expressed and secreted [RANTES], apolipoprotein A2 [ApoA2], transthyretin [TTR], and secretory vascular cell adhesion molecule-1 [sVCAM-1]), we tested various sets of biomarkers for their diagnostic performance in lung cancer. RESULTS: In a training dataset, the area under the curve (AUC) values were 0.821 for HE4, 0.753 for CEA, 0.858 for RANTES, 0.867 for ApoA2, 0.830 for TTR, and 0.552 for sVCAM-1. A model using all 6 biomarkers and age yielded an AUC value of 0.986 and sensitivity of 93.2% (cutoff at specificity 94%). Applying this model to the validation dataset showed similar results. The AUC value of the model was 0.988, with sensitivity of 93.33% and specificity of 92.00% at the same cutoff point used in the validation dataset. Analyses by stages and histologic subtypes all yielded similar results. CONCLUSIONS: Combining multiple tumor and systemic inflammatory markers proved to be a valid strategy in the diagnosis of lung cancer.

Diagnostic Value of Combining Tumor and Inflammatory Markers in Lung Cancer

In Table 2 and 3, cutoff values of RANTES, ApoA2, TTR, Svcam-1 (and sensitivity and specificity values accordingly) were wrongly marked.

A Case of Streptococcal Toxic Shock Syndrome Caused by Group A Streptococcus Pneumonia / 대한내과학회지

Streptococcal toxic shock syndrome (TSS) is characterized clinically by shock and multiple organ failure, combined with invasive group A streptococcus (GAS) infection. Invasive GAS infection declined with the introduction of modern antibiotics, but has recently arisen again globally with severe presentations like TSS. Cases of streptococcal TSS have been reported in Korea since the 1990s and its prevalence may increase. We report the first case of GAS pneumonia initially presenting as streptococcal TSS, as a warning that this potentially fatal illness requires an early diagnosis and prompt treatment when patients with pneumonia develop shock and multiple organ failure.

Successful High Flow Nasal Oxygen Therapy for Excessive Dynamic Airway Collapse: A Case Report / 결핵및호흡기질환

Excessive dynamic airway collapse (EDAC) is a disease entity of excessive reduction of the central airway diameter during exhalation, without cartilage collapse. An 80-year-old female presented with generalized edema and dyspnea at our hospital. The patient was in a state of acute decompensated heart failure due to pneumonia with respiratory failure. We accordingly managed the patient with renal replacement therapy, mechanical ventilation and antibiotics. Bronchoscopy confirmed the diagnosis of EDAC. We scheduled extubation after the improvement of pneumonia and heart condition. However, extubation failure occurred due to hypercapnic respiratory failure with poor expectoration. Her EDAC was improved in response to high flow nasal oxygen therapy (HFNOT). Subsequently, the patient was stabilized and transferred to the general ward. HFNOT, which generates physiologic positive end expiratory pressure (PEEP) effects, could be an alternative and effective management of EDAC. Further research and clinical trials are needed to demonstrate the therapeutic effect of HFNOT on EDAC.

Readmission to Medical Intensive Care Units: Risk Factors and Prediction

PURPOSE: The objectives of this study were to find factors related to medical intensive care unit (ICU) readmission and to develop a prediction index for determining patients who are likely to be readmitted to medical ICUs. MATERIALS AND METHODS: We performed a retrospective cohort study of 343 consecutive patients who were admitted to the medical ICU of a single medical center from January 1, 2008 to December 31, 2012. We analyzed a broad range of patients' characteristics on the day of admission, extubation, and discharge from the ICU. RESULTS: Of the 343 patients discharged from the ICU alive, 33 (9.6%) were readmitted to the ICU unexpectedly. Using logistic regression analysis, the verified factors associated with increased risk of ICU readmission were male sex [odds ratio (OR) 3.17, 95% confidence interval (CI) 1.29-8.48], history of diabetes mellitus (OR 3.03, 95% CI 1.29-7.09), application of continuous renal replacement therapy during ICU stay (OR 2.78, 95% CI 0.85-9.09), white blood cell count on the day of extubation (OR 1.13, 95% CI 1.07-1.21), and heart rate just before ICU discharge (OR 1.03, 95% CI 1.01-1.06). We established a prediction index for ICU readmission using the five verified risk factors (area under the curve, 0.76, 95% CI 0.66-0.86). CONCLUSION: By using specific risk factors associated with increased readmission to the ICU, a numerical index could be established as an estimation tool to predict the risk of ICU readmission.

Prevalence of Spirometrically-defined Restrictive Ventilatory Defect in Korea: The Fourth-2, 3, and Fifth Korean National Health and Nutrition Examination Survey, 2008-2012

The aim of the study was to evaluate the prevalence of restrictive ventilatory defect and to determine the risk factors in subjects with spirometrically-defined restrictive ventilatory defect. We used the population-based, fourth-2, 3 (2008, 2009) and fifth (2010-2012) Korea National Health and Nutrition Examination Survey (KNHANES) to analyze 15,073 subjects, aged > or =40 yr who underwent spirometry. Chest radiographs were also analyzed to identify restrictive lung disease. Spirometrically-defined restrictive ventilatory defect (FEV1/FVC> or =70% and FVC or =40 yr. The prevalence increased to 12.3% on using the lower limit of normal (LLN) criteria. Approximately 99.4% of subjects were classified as mild restrictive. Among these, 11.3% had inactive tuberculosis (TB) lesion, 2.2% cardiac disease, 2.0% previous operation scar or radiation injury and/or mediastinal disease, and 7.4% other pulmonary disease suggestive of restrictive lung diseases on chest radiograph. Evidence of previous TB history was independently associated with restrictive ventilatory defect (odds ratios [OR], 1.78; 95% confidence interval, 1.45-2.18) after adjustment for gender, age, smoking, area for residence and body mass index. The prevalence of restrictive ventilatory defect among the nationwide population in Korea was 11.3% with fixed ratio criterion and 12.3% with LLN criterion. Most cases were of the mild restrictive category and previous TB history is the independent risk factor for restrictive ventilatory defect.